This invention relates to a pressurizing cap for use in pressurizing a container of the type having at least one sidewall that defines an open end, and an annular lip extending radially from the open end. As described below this pressurizing cap may be used to provide a pressurized storage environment for racket-sport balls such as tennis balls.
Racket-sport balls such as tennis balls are originally packaged in pressurized containers, and such balls begin to deteriorate when the containers are opened and the balls are kept at atmospheric pressure. In the past, several approaches have been suggested for pressurizing containers that can be used to increase the effective life of such balls, as disclosed in the following patents:
______________________________________ U.S. Pat. No. Inventor(s) ______________________________________ 4,020,948 Won 4,019,629 Dubner, et al. 3,897,874 Coons 3,888,347 Kramer 3,853,222 Helms 3,819,040 Coons 3,581,881 Hobbs 3,233,727 Wilson 1,911,125 Miller 1,910,930 Morris ______________________________________
As illustrated by the Wilson. Miller and patents, one approach is to provide a pressurizing container with a valve that allows pressurized air to be admitted into the container. Another approach is to supply a piston pump as an integral part of the container, as disclosed in the Kramer, Dubner, Helms and Morris patents. The Dubner and Helms patents disclose caps that include integral pumps, and that are designed for use with conventional tennis ball containers.
Another approach as illustrated by the Won and Coons patents is to provide a container having an externally threaded base and an internally threaded lid. The base and lid are provided with seals such that rotation of the lid simultaneously moves the lid to the closed position and pressurizes the internal volume contained by the body and the lid. A major disadvantage of this approach is that it requires a custom container having external threads to receive the lid.
It is an object of this invention to provide an improved, simplified pressurizing cap which preferably can be used with a conventional container to pressurize the contents of the container.